Marcos Santander | IceCube | USA

DOMs away!

2010 has been a very fruitful year for IceCube, and the grand finale for the year could not have been better with the completion of the detector on December 18th.

Many of us were following the events unfolding at the South Pole through a live video feed, and although it was not HD video, it wasn’t hard to notice the smiles in the faces of the people working on the last string of light sensors to go down into the ice. At around 6 pm New Zealand time the 86th and final IceCube string was secured in place, a great ending for a story that had started 7 years before, with the drilling of the first IceCube hole.

The successful completion of the telescope owes much to the development of the hot water drill that is able to make its way through 2.5 km of solid Antarctic ice, making room for the strings of 60 DOMs (Digital Optical Modules) that go into the ice. The first step in the drilling process is to penetrate the ~50 m thick firn layer (i.e. compacted snow). The drill in charge of this part has a copper coil through which hot water is pumped, melting the snow around it.

As soon as the actual ice is reached, the firn drill is replaced by the hot water drill. The drill creates a hole in the ice by sending a highly pressurized stream of hot water that is able to melt more than 750 metric tons of ice (200000 gallons) in about 48 hours, reaching a depth of 2.5 km (1.5 mi). Almost 18000 liters (4800 gallons) of airplane fuel are used to drill each hole.

After that, it is time for the deployment crew to attach the DOMs to the cable string and send them down the hole, in an operation that takes about 11 hours.

Here you have a video of the last DOM, named “Moa”, being lowered into the hole.

And a short video of the same DOM disappearing into the pond of water in the last hole

Even though IceCube has been producing science for a while, having the entire detector will increase the amount and quality of the data we take.